first of all: usually there is no direct feedback between the frequency of the VCO and the voltage output of the µTune. So you will need to use the tuner to set up your VCO correctly.
This will change with the upcoming autotuning feature, but here I am describing an open loop approach.
Play any note that you wont to have 432 Hz. Using µTune’s tuner, adjust the frequency of your VCO to 432Hz.
If you want to create a scale for specific frequencies, have a look at :